In late 2013, Powes Parkop instituted a ban on the public sale and consumption of the stimulant, known locally as 'buai', in the National Capital District.

The NCD has now relaxed restrictions on vendors selling buai, but the total ban will remain on chewing it in public.

Mr Parkop concedes the ban had a financial impact on small-scale vendors who rely on income from selling buai, and that lives were lost trying to smuggle it in to the city.

However he said overall, the ban had been beneficial.

"The city's much better because it's much cleaner, people's habit and behaviour has changed in terms of spitting everywhere and the image of the city is much better. We are improving people's hygiene, people's health. People are more conscious about their health now than they were before the ban."

Mr Parkop said he expected rates of cancer relating to betel nut chewing would decrease as a result of the ban

A fine of 500-Kina, or equivalent community work, will be enforced on those who ignore the ban.